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Human Induced Pluripotent Stem Cells on Autologous Feeders  [PDF]
Kazutoshi Takahashi,Megumi Narita,Midori Yokura,Tomoko Ichisaka,Shinya Yamanaka
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008067
Abstract: For therapeutic usage of induced Pluripotent Stem (iPS) cells, to accomplish xeno-free culture is critical. Previous reports have shown that human embryonic stem (ES) cells can be maintained in feeder-free condition. However, absence of feeder cells can be a hostile environment for pluripotent cells and often results in karyotype abnormalities. Instead of animal feeders, human fibroblasts can be used as feeder cells of human ES cells. However, one still has to be concerned about the existence of unidentified pathogens, such as viruses and prions in these non-autologous feeders.
Characterizing the Radioresponse of Pluripotent and Multipotent Human Stem Cells  [PDF]
Mary L. Lan, Munjal M. Acharya, Katherine K. Tran, Jessica Bahari-Kashani, Neal H. Patel, Jan Strnadel, Erich Giedzinski, Charles L. Limoli
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0050048
Abstract: The potential capability of stem cells to restore functionality to diseased or aged tissues has prompted a surge of research, but much work remains to elucidate the response of these cells to genotoxic agents. To more fully understand the impact of irradiation on different stem cell types, the present study has analyzed the radioresponse of human pluripotent and multipotent stem cells. Human embryonic stem (ES) cells, human induced pluripotent (iPS) cells, and iPS-derived human neural stem cells (iPS-hNSCs) cells were irradiated and analyzed for cell survival parameters, differentiation, DNA damage and repair and oxidative stress at various times after exposure. While irradiation led to dose-dependent reductions in survival, the fraction of surviving cells exhibited dose-dependent increases in metabolic activity. Irradiation did not preclude germ layer commitment of ES cells, but did promote neuronal differentiation. ES cells subjected to irradiation exhibited early apoptosis and inhibition of cell cycle progression, but otherwise showed normal repair of DNA double-strand breaks. Cells surviving irradiation also showed acute and persistent increases in reactive oxygen and nitrogen species that were significant at nearly all post-irradiation times analyzed. We suggest that stem cells alter their redox homeostasis to adapt to adverse conditions and that radiation-induced oxidative stress plays a role in regulating the function and fate of stem cells within tissues compromised by radiation injury.
MicroRNAs and Induced Pluripotent Stem Cells for Human Disease Mouse Modeling
Chingiz Underbayev,Siddha Kasar,Yao Yuan,Elizabeth Raveche
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/758169
Abstract: Human disease animal models are absolutely invaluable tools for our understanding of mechanisms involved in both physiological and pathological processes. By studying various genetic abnormalities in these organisms we can get a better insight into potential candidate genes responsible for human disease development. To this point a mouse represents one of the most used and convenient species for human disease modeling. Hundreds if not thousands of inbred, congenic, and transgenic mouse models have been created and are now extensively utilized in the research labs worldwide. Importantly, pluripotent stem cells play a significant role in developing new genetically engineered mice with the desired human disease-like phenotype. Induced pluripotent stem (iPS) cells which represent reprogramming of somatic cells into pluripotent stem cells represent a significant advancement in research armament. The novel application of microRNA manipulation both in the generation of iPS cells and subsequent lineage-directed differentiation is discussed. Potential applications of induced pluripotent stem cell—a relatively new type of pluripotent stem cells—for human disease modeling by employing human iPS cells derived from normal and diseased somatic cells and iPS cells derived from mouse models of human disease may lead to uncovering of disease mechanisms and novel therapies.
The Promise of Human Induced Pluripotent Stem Cells in Dental Research  [PDF]
Thekkeparambil Chandrabose Srijaya,Padmaja Jayaprasad Pradeep,Rosnah Binti Zain,Sabri Musa,Noor Hayaty Abu Kasim,Vijayendran Govindasamy
Stem Cells International , 2012, DOI: 10.1155/2012/423868
Abstract: Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC lines in vitro from patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders. 1. Introduction Human embryonic stem cells (hESCs) are pluripotent cells, which have remarkable proliferation ability to differentiate into any cell types of all three germ layers in a defined culture condition. Hence embryonic stem cells have been regarded as the most potent tool for experimental studies, drug screening, and regenerative medicine [1]. However, the ethical dilemmas regarding the donation or destruction of human embryos and the immunoincompatibility of hESCs have impeded its application in cell-based therapy [1]. In order to overcome these problems, reprogramming techniques have been introduced where somatic cells can be reversed into a pluripotent stem cell-like state. It is generally believed that induced pluripotent stem (iPSC) cells might demonstrate the potential for alleviating incurable diseases and aiding organ transplantation [2]. It has been shown that iPSCs can be derived efficiently from various human cell types [3–8]. An interesting observation is that the transcriptional and epigenetic features of iPSCs are reported to be similar to hESCs [9–11]. Nevertheless, further insights into the inherent similarities and differences between hESCs and iPSCs would be advantageous in understanding the reasons why the use of hESCs in clinical and translational applications has been held back [12, 13]. 2. Generation of Induced Pluripotent Stem Cells Induced pluripotent stem cells can be produced by forced expression of certain genes by reversing them to a pluripotent state similar to that of embryonic stem
Transcriptional Signature and Memory Retention of Human-Induced Pluripotent Stem Cells  [PDF]
Maria C. N. Marchetto, Gene W. Yeo, Osamu Kainohana, Martin Marsala, Fred H. Gage, Alysson R. Muotri
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0007076
Abstract: Genetic reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells or iPSCs) by over-expression of specific genes has been accomplished using mouse and human cells. However, it is still unclear how similar human iPSCs are to human Embryonic Stem Cells (hESCs). Here, we describe the transcriptional profile of human iPSCs generated without viral vectors or genomic insertions, revealing that these cells are in general similar to hESCs but with significant differences. For the generation of human iPSCs without viral vectors or genomic insertions, pluripotent factors Oct4 and Nanog were cloned in episomal vectors and transfected into human fetal neural progenitor cells. The transient expression of these two factors, or from Oct4 alone, resulted in efficient generation of human iPSCs. The reprogramming strategy described here revealed a potential transcriptional signature for human iPSCs yet retaining the gene expression of donor cells in human reprogrammed cells free of viral and transgene interference. Moreover, the episomal reprogramming strategy represents a safe way to generate human iPSCs for clinical purposes and basic research.
State of the Art in Stem Cell Research: Human Embryonic Stem Cells, Induced Pluripotent Stem Cells, and Transdifferentiation  [PDF]
Giuseppe Maria de Peppo,Darja Marolt
Journal of Blood Transfusion , 2012, DOI: 10.1155/2012/317632
Abstract: Stem cells divide by asymmetric division and display different degrees of potency, or ability to differentiate into various specialized cell types. Owing to their unique regenerative capacity, stem cells have generated great enthusiasm worldwide and represent an invaluable tool with unprecedented potential for biomedical research and therapeutic applications. Stem cells play a central role in the understanding of molecular mechanisms regulating tissue development and regeneration in normal and pathological conditions and open large possibilities for the discovery of innovative pharmaceuticals to treat the most devastating diseases of our time. Not least, their intrinsic characteristics allow the engineering of functional tissues for replacement therapies that promise to revolutionize the medical practice in the near future. In this paper, the authors present the characteristics of pluripotent stem cells and new developments of transdifferentiation technologies and explore some of the biomedical applications that this emerging technology is expected to empower. 1. Introduction Stem cells represent the building blocks of our bodies, functioning as the natural units of embryonic generation during development, and adult regeneration following tissue damage [1]. They are defined by two distinct characteristics: the ability to maintain themselves through cell division, sometimes after long periods of inactivity (self-renewal), and the ability to give rise to more specialized cell types (differentiation) [2]. Based on the stage in development they are derived from, stem cells are broadly classified as embryonic, umbilical cord, and adult stem cells. Potency of stem cells decreases during development from totipotent stem cells at the morula stage, capable of differentiating into all embryonic and extraembryonic tissues, to pluripotent stem cells at the blastocyst stage, forming all embryonic tissues, and to multi- or uni-potent adult stem cells, forming tissues within their germ layer (Figure 1). Figure 1: Human pluripotent stem cells and their biomedical applications. hESCs are isolated from early embryos obtained by in vitro fertilization or nuclear transfer, and give rise to more specialized cells (pink arrows). Alternatively, reprogramming technologies allow generation of hIPS from differentiated cells, or lineage conversion between differentiated cell types (black arrows). Developmental biology studies are unraveling the characteristics of cell types found at different stages. Stem cells and their differentiated progeny are used in a variety of biomedical
Isolation and Characterization of Multipotent and Pluripotent Stem Cells from Human Peripheral Blood  [PDF]
Ciro Gargiulo, Van Hung Pham, Nguyen Thuy Hai, Kieu C. D. Nguyen, Pham Van Phuc, Kenji Abe, Veronica Flores, Melvin Shiffman
Stem Cell Discovery (SCD) , 2015, DOI: 10.4236/scd.2015.53003
Abstract: Stem cells are commonly classified based on the developmental stage from which they are isolated, although this has been a source of debate amongst stem cell scientists. A common approach classifies stem cells into three different groupings: Embryonic Stem Cells (ESCs), Umbilical Cord Stem Cells (UCBSCs) and Adult Stem Cells (ASCs), which include stem cells from bone marrow (BM), fat tissue (FT), engineered induced pluripotent (IP) and peripheral blood (PB). By definition stem cells are progenitor cells capable of self-renewal and differentiation hypothetically “ab infinitum” into more specialized cells and tissue. The main intent of this study was to determine and characterize the different sub-groups of stem cells present within the human PB-SCs that may represent a valid opportunity in the field of clinical regenerative medicine. Stem cells in the isolated mononucleated cells were characterized using a multidisciplinary approach that was based on morphology, the expression of stem cell markers by flowcytometry and fluorescence analysis, RT-PCR and the capacity to self-renew or proliferate and differentiate into specialized cells. This approach was used to identify the expression of hematopoietic, mesenchymal, embryonic and neural stem cell markers. Both isolated adherent and suspension mononucleated cells were able to maintain their stem cell properties during in-vitro culture by holding their capacity for proliferation and differentiation into osteoblast cells, respectively, when exposed to the appropriate induction medium.
Specification of Region-Specific Neurons Including Forebrain Glutamatergic Neurons from Human Induced Pluripotent Stem Cells  [PDF]
Hui Zeng,Min Guo,Kristen Martins-Taylor,Xiaofang Wang,Zheng Zhang,Jung Woo Park,Shuning Zhan,Mark S. Kronenberg,Alexander Lichtler,Hui-Xia Liu,Fang-Ping Chen,Lixia Yue,Xue-Jun Li,Ren-He Xu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011853
Abstract: Directed differentiation of human induced pluripotent stem cells (hiPSC) into functional, region-specific neural cells is a key step to realizing their therapeutic promise to treat various neural disorders, which awaits detailed elucidation.
Generation and Characterization of Erythroid Cells from Human Embryonic Stem Cells and Induced Pluripotent Stem Cells: An Overview  [PDF]
Kai-Hsin Chang,Halvard Bonig,Thalia Papayannopoulou
Stem Cells International , 2011, DOI: 10.4061/2011/791604
Abstract: Because of the imbalance in the supply and demand of red blood cells (RBCs), especially for alloimmunized patients or patients with rare blood phenotypes, extensive research has been done to generate therapeutic quantities of mature RBCs from hematopoietic stem cells of various sources, such as bone marrow, peripheral blood, and cord blood. Since human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) can be maintained indefinitely in vitro, they represent potentially inexhaustible sources of donor-free RBCs. In contrast to other ex vivo stem-cell-derived cellular therapeutics, tumorigenesis is not a concern, as RBCs can be irradiated without marked adverse effects on in vivo function. Here, we provide a comprehensive review of the recent publications relevant to the generation and characterization of hESC- and iPSC-derived erythroid cells and discuss challenges to be met before the eventual realization of clinical usage of these cells. 1. Introduction Medical progress, specifically in the fields of hematology/oncology and transplantation surgery, as well as an overall aging population, has led to an ever-increasing demand for erythrocytes for transfusion to currently approximately fifty thousand RBC concentrates per million population per year in countries with a high standard of health care. Currently, the exclusive source for these is volunteer donors, who obviously are subject to the same societal changes as the recipients, that is, they are aging also. Recruitment of new donors from the shrinking pool of eligible individuals is challenging and additionally hampered by ever-increasing restrictions, predominantly recipient-directed exclusion criteria for donors. Perceived lack of safety of blood products also is a highly sensitive issue in the population, particularly since the emergence of HIV in the eighties, as a consequence of which a whole generation of hemophilia patients was infected. The desire to counter these challenges has led to the extensive effort in the generation of red blood cells (RBCs) in vitro from a variety of sources, such as bone marrow, peripheral blood, and cord blood. More recently, utilizing embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) to generate universal donor RBCs has been envisioned [1, 2]. hESCs are pluripotent stem cells derived from the inner cell mass of the blastocyst [3], and iPSCs are ESC-like cells generated by reprogramming somatic cells, most often via forced expression of a combination of transcription factors, such as Oct3/4, Nanog, KLF4, c-Myc, LIN28, and
Modeling Neurological Disorders by Human Induced Pluripotent Stem Cells
Tanut Kunkanjanawan,Parinya Noisa,Rangsun Parnpai
Journal of Biomedicine and Biotechnology , 2011, DOI: 10.1155/2011/350131
Abstract: Studies of human brain development are critical as research on neurological disorders have been progressively advanced. However, understanding the process of neurogenesis through analysis of the early embryo is complicated and limited by a number of factors, including the complexity of the embryos, availability, and ethical constrains. The emerging of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) has shed light of a new approach to study both early development and disease pathology. The cells behave as precursors of all embryonic lineages; thus, they allow tracing the history from the root to individual branches of the cell lineage tree. Systems for neural differentiation of hESCs and iPSCs have provided an experimental model that can be used to augment in vitro studies of in vivo brain development. Interestingly, iPSCs derived from patients, containing donor genetic background, have offered a breakthrough approach to study human genetics of neurodegenerative diseases. This paper summarizes the recent reports of the development of iPSCs from patients who suffer from neurological diseases and evaluates the feasibility of iPSCs as a disease model. The benefits and obstacles of iPSC technology are highlighted in order to raising the cautions of misinterpretation prior to further clinical translations.
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